1. Field of the Invention
The present invention relates to a radio frequency (RF) switch circuit and, more particularly, to an RF switch circuit in which an RF switch and a switch controller are formed on a single CMOS substrate and floating resistors are connected to a deep N type well substrate, an N type well substrate, and a P type well substrate to thereby increase linearity with respect to input power.
2. Description of the Related Art
Recently, wireless communication terminals have been widely used thanks to the convenience of their use. Wireless communication terminals may employ an RF switch circuit in order to change a transmission path of an RF signal.
The RF switch circuit may include an RF switch for changing a signal path and a controller for controlling the RF switch.
The RF switch circuit has largely been made of compound semiconductor such as SOS (Silicon on Sapphire), SOI (Silicon on Insulator) or gallium-arsenide (GaAs), but recently, due to an increase in the fabrication cost and a CMOS (Complementary Metal Oxide Semiconductor) process and circuit design technique development, the RF switch circuit is increasingly fabricated through the CMOS process.
However, the CMOS process is disadvantageous in that an insertion loss increases due to high parasitic capacitance, and because a breakdown voltage is low, if the power of an input signal to the RF switch is large, the insertion loss further increases and linearity deteriorates.